<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>Title</title>
</head>
<body>
    <div>
        <p>
            <a onclick="Add(this)">+</a>
            <input type="text">
        </p>
    </div>
<script src="jquery-3.5.0.js"></script>
<script>
    function Add(ths) {
        var tag = $(ths).parent().clone();

        tag.find('a').text('-');
        tag.find('a').attr('onclick','Remove(this)');
        $(ths).parent().parent().append(tag);
    }
    function Remove(ths) {
        $(ths).parent().remove();
    }
</script>
</body>
</html>